Arrangement for localizing disturbed areas in electric mains



July 1 1924. 1,500,003

, P. SCHADE ARRANGEMENT FOR LOCALIZING DISTURBED AREAS IN ELECTRIC MAINS May 5, 1922 Fil Inventor: Paul Schade,

y %IM% His Attorney.

Patented July 1, 1924.

UNITED STATES PATENT OFFICE.

PAUL SGHADE, OF HERMSDOR'E, NEAR, BERLIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ARRANGEMENT FOR LOCALIZING DISTURBED AREAS IN ELEC'IR-IG MAINS.

Application filed May 3,

To all whom it may concern:

' Be it known that I, PAUL SCHADE, a citizen of the German Republic, residing at 14 Kneippstn, Hermsdorf, near Berlin, Germany, have invented certain new and useful Improvements in Arrangements for Localizing Disturbed Areas in ElectricMains, of which the following is a specification.

This invention relatesto an arrangement for localizing disturbed areas in electric mains.

It has already been proposed to localize disturbed areas in electric mains, the sections of which consist of several parallel branches,

by utilizing the voltage drop between corresponding points of the different branches.

For this purpose each of the brancheswith the exception of the two outer ones is connected with two other branches across voltage coils and the voltage coils placed in the connecting leads co-operate with current coils in the parallel conductors of the system.

The branch of the mains in which the voltage drop differs from that in the other -branches is then automatically cut out of circuit.

Cases may, however, occur in which this arrangement will no longer work with certainty. In particular failure may arise if the system is mainly loaded inductively. In order to effect also the cutting out of the disturbed section with certainty, the improved arrangement according to this invention, is such, that the connecting leads are united to form a completely closed connecting circuit. The possibility is then given to effect the interruption of the current by means of relays, in which merely the voltage coils placed in the connecting leads 'co-operate, while the current coils placed in the parallel branches in the known arrangement are eliminated. I

In the connection of the branches of the mains by a closed connecting circuit a difiiculty arises, however, in the case of an even number of parallel branches. If, for instance, there exist, as shownin the drawing, four parallelbranches 123 1 and a fault occurs in branch 1, a balancing current flows to this branch across the connecting leads in one from the branches 3 -2-1 1922. Serial No. 558,224.

and in another path from the branches 311. In the connecting leads which be long to the branches 2, 4 there flows a current directed towards the branch and a current directed away from the branch, so that the relays belonging to this branch do not come into action. In the branch 3 on the other hand the direction of the current in the connecting leads belonging to it is the same, that means either towards the branch or away from it, exactly as in the disturbed branch. Consequently the relays for these two branches 1, 3 respond simultaneously. Besides the faulty branch 1 thus the sound branch 3 is also cut out.

This undesired cutting out of a sound branch from several parallel branches may be avoided by providing between the branches not one only, but at least two connecting circuits. Care must, however, be taken that the succession of the branches with relation to the connecting circuits of the parallel branches is a difierent one and two branches which in relation to the connecting circuit are situated at 180 opposite each other must not have this situation in relation to the other connecting circuit. The relays of the various connecting circuits belonging to a certain branch are then brought into co-operation in any suitable manner and operate for instance series contacts of an auxiliary circuit. so that the cutting out of the faulty branch only takes place, since in each of the connecting circuits the connecting leads belonging to the branch in question show the same directions of the currents.

In the drawing the improved arrangementis shown in a case in which the section of the mains consists of four parallel branches and always two complete connecting circuits co-operate. The parallel branches are indi cated by the letters of reference (1,, a a and o They are, at the sub-stations, directly connected in the customary way by bus bars a and 7). Of the two connecting circuits serving for the guarding and automatic cutting out, the one contains the volt age coils 0 c c c c c 0 c, and the other the voltage coils d 6Z (5,, d d (5 d In the former the succession of the sep arate parallel branches is such, that the connecting circuit starting from (L passes across an, a a and hence back to on, while the second connecting circuit starts -from a and passes across a a a back to c Between the points of the mains connected by the b bar I) an he point connec ed y th balancing circuit, choking coils e are placed in the parallel branches for the purpose of artificially increasing the voltage drop. In each of the parallel branches in, a ,a a there is also placed a switch Arranged to be operated by the coils c and (Z are the relays 9 provided for the purpose of closing the circuits by which the various operating coils in of the switches f are connected to a suitable source of current. A catch '5 biased to a position in which it engages a projection on the operating rod of; the switch may be utilized for the purpose of locking the switch in openposition. Any other suitable means may be used for the purpose of opening one of the switches f in response to the condition produced in the coils c and oi by a fault on one of the branches of the main.

If a fault occurs in the branch 0a balancing currents will appear in the connecting circuit. ht a certain moment the direction of the flux produced by the various coils, 0 and (Z is as indicated in the drawing by arrows. For the first connecting circuit the arrows start at both sides from the branch a and meet at the branch an. In the other connecting circuit on the the other hand the arrows start from the branch on and meet at the branch a owing to the altered succession of the parallel branches.

The relay afiected by the coils 0 and 0 on the one hand and the relay affected by the coils and (1 on the other hand then both operate to cut out the branch a by opening the switch 7 placed in this branch. All the other branches remain in circuit as in them, not more than the relay'in one of; the connecting circuits is operated to out out the branch.

It will be understood that the arrangement may be varied in details without departing from the spirit of the invention.

\Vhat I claim as my invention and desire to secure by Letters Patent is:

1. A system of the class described comprising a busbar, a plurality of conductors arranged to be interconnected with said bus bar, a. plurality of switches each arranged to connect one of said conductors to said bus bar, and means comprising a plurality of closed circuits each arranged to intercom nect all of said conductors in different succession for selectively operating said switches to disconnect any conductor in which a fault occurs.

2. A system of the class described comprising a bus bar, a plurality of conductors arranged to be interconnected with said bus bar, a plurality of switches each arranged to connect one of said conductors to said bus bar, and a plurality of relays each arranged to control the operation of one of said switches in response to a fault in the corresponding conductors, the operatingcoils of said relays being connected in a closed circuit arranged conductively to interconnect corresponding points of said conductors.

3. A system of the class described comprising a bus bar, a plurality of conductors arranged to be interconnected with said bus bar, a plurality of switches each arranged to connect one of said conductors to said bus bar, a relay adapted to control the opera tion of each switch and provided with operating coils connected in a closed circuit arranged to interconnect said conductors in one succession, a second relay adapted to control the operation of each switch and provided-with operating coils connected in a 1 second closed circuit arranged to intercon nect said conductors in a different succession, and an operating coil for, each switch which is arranged'to be energized only when the corresponding relay in each closed circuit is energized. V a. A system of the prising a bus bar, a plurality of conductors arranged to be interconnected with said bus bar, a plurality of switches each arranged to connect one of said conductors to said bus bar, a relay adapted to control theoperation of each switch and provided with operating coils connected in a closed circuit arranged to interconnect said conductors in 7 one succession, a second relay adapted to control the operation of each switch and provided with operating coils connected in a second closed circuit arranged to interconnect said conductors in a difierent succession, an operating coil for each switch which isarranged to be energized only when the corresponding relay in each closed circuit is energized, and a plurality of choke coils each arranged to be connected in series with one of said conductors. V V

5. A system of the class describedco nprising a bus bar, a plurality of conductors arranged to be interconnected with said bus bar, a plurality of switches each arranged arranged to be interconnected with said bus nected in a different closed circuit and all bar, a plurality of switches each arranged of said closed circuits being arranged to to connect one of said conductors to said connect said conductors in different succes- 1 bus bar, a plurality of groups of relays each sion.

5 group being adapted to control the opera- In testimony whereof I aflix my signation of one of said switches, the operating ture.

coils of each relay in a group being con- PAUL SCHADE. 

